Symplectic fixed points, the Calabi invariant and Novikov homology
Symplectic fixed points, the Calabi invariant and Novikov homology
复制标题
辛不动点、卡拉比不变量和诺维科夫同调
DOI:
10.1016/0040-9383(94)e0015-c
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发表时间:
1995
期刊:
影响因子:
--
通讯作者:
K. Ôno
中科院分区:
文献类型:
--
作者:
L. Vân;K. Ôno
A symplectic structure w on a manifold M provides the one-to-one correspondence between closed 1-forms and infinitesimal automorphisms of (M, w), ie vector fields X satisfying L. xW= O. An infinitesimal automorphism X is called a. Hamiltonian vect'or field, if it corresponds to a exact l~ form. A symplectomorphism ep on M is called exact, if it is the time 1 map of a time-depending Hamiltonian vector field. In fact, one can find a. periodic Hamiltonian function such that rp is the time 1 map of the Hamiltonian system. For each symplectomorphism ep isotopic to the identity through symplectomorphisms, oue ean assign a cohomology class Cal (ep), which is called the Calabi invariant of rp Banyaga [B] showed that rp is exact if and only if Cal (rp)= O. The Arnold conjecture states that the number of fixed points of an exact symplectomorpbism on a compaet syrnplectic manifold ean be estirnated below by the surn of the Betti numbers of M provided that a11 the fixed points are non-degenerate. Arnold came to this conjecture by analysing the case that rp is elose to tbe identity (see [AJ). If rp is the time 1 map of a time-independent Hamiltonian vector field corresponding to a Morse function f which is C~-small, the fixed points eoincides with the critical points of fand the conjecture ia verified in this case, which is nothing hut the Morse theory.There are many partial resuIts in the Arnold conjeeture. A great progress was done by Floer, who combined the variational approach (see [CZ]) and theory of pseudüholomorphic curves due to Gromov and proved the Arnold conjeeture for monotone'symplectic manifolds [Fl]. He developed an analogue of the Morse theory for the action funetional on the loop space and led to the notion of Floer homology. The Arnold conjecture is derived from the fact that the Floer homology group is isomorphie to the ordinary homology group of M. Recently, Hofer and Salamon [HS] define the Floer homology group for a wider dass of symplectic manifolds (which are called weakly monotone sympleetie manifolds). An almost complex strueture J on M is calibrated by w, if